Spin polarization engineering in d -wave altermagnets

Altermagnets host unconventional spin-polarized bands despite zero net magnetization, but controlling their spin structure remains challenging. We propose a multi-field approach to engineer spin polarization in $d$-wave altermagnets using gating, optical driving, and in-plane electric fields, which enable tunable and switchable polarizations along multiple directions. Optical driving induces out-of-plane ($z$) polarization, while gating and in-plane fields generate $x$- and $y$-polarizations via the Edelstein effect, all of which are experimentally detectable. We further find that spin- and band-selective doping induces chiral optical activity, a feature unique to altermagnets. Our approach provides a…

• UD
  U.S. Department of Energy

  Award: DE-FG02-08ER46542
• KO
  Knut och Alice Wallenbergs Stiftelse

  Awards: 2023.0336, 2022.0079
• V
  Vetenskapsrådet

  Award: 2022-06725
• NF
  Norges Forskningsråd

  Awards: 353894, 262633
• ER
  European Research Council

  Award: 101165122